Liquid indicator and strainer for refrigerating systems



2 SHEETS-SHEET l R S GRAVES EI'AL LIQUID INDICATOR AND STRAINER FOR REFRIGERATING SYSTEMS Filed on. 25. 1950 Aug. 26, 1952 1952 R. s. GRAVES EIAL LIQUID INDICATOR AND STRAINER FOR REFRIGERATING SYSTEMS Filed Oct. 23, 1950 2 SHEETS-SHEET 2 A 0 INVENTORQ R .8. rave 5' ,Do a ZoneB. 6 61:9673 J7".

ATTORNEY Patented Aug. 26, 1952 ,LIQUID INDICATOR AND STRAINER FOR REFRIGERATING SYSTEMS V k Robert Spencer Graves and D'octone Benjamin Geiger, Jr., Columbus, Ga.

Application October 23, 1950, Serial No. 191,542

This invention relates to refrigerating systems.

An object of this invention is to provide a device adapted, for insertion in a refrigeration system at the intake side of the expansion valve whereby the condition of the refrigerant liquid may be viewed and the movement of the liquid to the expansion valve can be checked without disconnecting any portion of the' system.

Another object of this invention is to provide an attachment for a'refrigerating system which is of simple construction and can be interposed in the system without changing any of the elements in the system.

An important object of this invention is to provide a device of the kind herein disclosed to connect in the inlet of an expansion valve on a refrigeratin system, with a strainer in the glass of the liquid indicator, the strainer being clearly visible in order that dirt or foreign material which would cause the refrigerant to cease flowing can be readily detected and thus obviate the need of taking the system apart to determine, for example, why the machine is being starved of refrigerant or in the case of an installation having more than one coil or evaporator, as to why one of the latter is being starved. Experience has shown that the fault is likely to be a stoppage at the inlet 01 the expansion valve.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a diagrammatic view of a refrigeratin system of conventional construction having an attachment constructed according to an embodiment of this invention interposed therein.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a front elevation of the attachment.

Figure 4 is a sectional view taken on the line 4-4 of Figure 2.

Referring to the drawings, and, first, to Figure 1 wherein there is disclosed a conventional refrigerating system, a compressor I is connected by means of a pipe I l to a condenser 12, and the outlet side of the condenser 12 is connected by means of a pipe l3 to a liquid receiver I 4. The outlet side of the receiver I4 is connected by means of a pipe [5 to a strainer I6, and the strainer I6 is connected by a pipe I! to an expansion valve Hi.

The outlet side of the expansion Valve I8 is connected by a pipe [9 to an evaporator 20, and

2'Claims. (Cl. 210-134) 2 the evaporator is connected by a pipe 2| to the suction or intake side of the compressor l0. A

control member 22 is connected with the pipe I9 for regulating the cycles of the refrigerating system. The system hereinbefore described is conventional and is illustrative of a system within which an attachment constructed according to this invention is adapted to be connected. The intake side of the expansion valve l8 which is normally connected with the pipe I! has interposed between the pipe I! and the valve [8 a combined sight member and strainer generally designated as 23. The combined sight member and strainer 23 is formed of a substantially cylindrical-member 24 which is formed with one or more oval windows 25 substantially midway between the ends thereof. A cap 26 which is formed with a threaded stud 21 is threaded onto the upper end of the cylindrical member 24 withthe stud 21 threaded into the boss 28 at the intake end of the expansion valve [8. i

i The lower end of .the cylindrical member 24 has threadedthereon a cap 23 which includes a threaded stud 30 engageable by a threaded coupling 3i connecting the upper end of the pipe I! with the sight and strainer member 23. A glass tube 32 is disposed within the cylindrical member 24 between the ends of the latter, and upper and lower sealing gaskets 33 and 34 bear against the opposite ends of the transparent tube 32. An upper spring 35 is disposed within the upper end of the cylindrical member 24 and bears at its upper end against the cap 26.

The opposite end of spring 35 bears against a metal washer 36 which in turn bears against the upper sealing gasket 33. A lower spring 31 is disposed in the lower portion of the cylindrical member 24 bearing at its lower end against lower cap 29 and bearing at its upper end against a metal washer 38 which engages against the sealing gasket 34. i

A cylindrical screen 39 is disposed in the lower portion of the cylindrical member 24 terminating at its upper end between the opposite ends of the window opening 25 so that a portion of the screen 39 may be viewed through the opening 25.

The screen 39 includes an upper wall 40 which provides a means whereby the liquid or refrigerant will be required to pass through the wall 40 of the screen, and this wall can readily be viewed through the glass tube 32 and the window opening 25.

The cylindrical screen member 39 projects downwardly through the spring 31 and the cap 29,

being disposed within the stud, 30 and formed with an annular lower flange 41 which bears against the lower end of the stud or nipple 30. The upper end of the pipe I! is formed with a flange 42 bearing against the screen flange 4! so that when the cap or cOupling member 3| is tightened on the nipple 30, the pipe I! will tightly hold the flange 4! of the screen against the lower end of the nipple 30.

Tightening of the caps 26 and 29 will also tension the springs 35 and 31 against compressing washers 36 and 38, respectively, so that the sight.

tube 32 will be tightly sealed within the cylindri cal member or housing 24.

The combined sight member and screen strainer parent tube within which said strainer is positioned in said member extending across said opening, a sealing washer at each end of said tube, and a spring at each end of said member one end of said spring bearing against a cap and the other end of said spring bearing against one of said washers whereby to place each washer under sealingpressure.

2. A liquid indicator providing means for viewing a strainer adapted to be interposed in a refrigerating system, comprising a tubular member having a. sight opening between th ends jthereof, a screw cap threaded on each end of structure should be a part of the expansionvalve or attached at the inlet of the expansion .valve. When the compressor [0 is operating, the liquid refrigerant I0 is forced through the combined frigerating system, and such cooling coils or evaporators will receive equal refrigerant so that such coils, will be maintained at the desired heat exchanging condition. Thisattachment can. be connected with, the refrigerating system without affecting the cyclic operation or the system and.

without changing the various parts and elements making upthe refrigerating system.

What is claimed is:;

1. A liquid indicatorproviding means for viewing a strainer adapted to be interposed in a refrigerating systemcomprising a tubular member having a sight opening between the ends thereof, a'screw cap on'each end of said member, threaded nipples carried by said caps, a transsaid member, threaded nipples carried by said 15 caps, atransparent tube in said member and extending across said opening, a sealing washer at each end of said tube, a springat each end of said transparent tube, one end of said spring bearing against acap and the other end of said 20 spring bearing against one of said washers wherebyto place each washer under sealing pressure, said strainer: comprising a tubular; screen in said tube: and terminating midway the length of said sight. opening, an inner screen wal1 carried by the inner end of said screen, and an annular flange carried by the outer end of said screen bearing against the adjacent outer end of one of said nipples, a. pipe having a flange bearing against the flange on the outer end of the screened wall and a threaded coupling secured to the one of said nipples and retaining the screen and the pipe against displacement from the one nipple.

ROBERT SPENCER GRAVES. DOCTONE BENJAMIN GEIGER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES, PATENTS Number Name Date 1,666,918 Scoville Apr. 24, 1928' 1,866,659 Little, Jr. July 12, 1932 2,265,550 V Smith Dec. 9, 1941 2,325,657

Burkness Aug. 3, 1943 

